Ancelotti coached Xabi at Real Madrid.
"He takes things very seriously, but at the same time he's smart enough not to joke, but he doesn't have such a meaningful way of saying things. He knows very well how to work with great players," he said.
"He has had an incredible career and with his character he knows how to approach the players. Sometimes he demands more from the players, sometimes he gives them more responsibility to take a step forward.
"He knows a lot about football. There are no secrets between Carlo and football. He has all that knowledge, but at the same time he studies and analyses the rival, but giving more importance and meaning to what his team can do."